This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. 4/30/2008 Recent functional MRI studies in patients with autism have found abnormally increased brain activity in areas that mediate basic, stimulus-driven processing and abnormally decreased activity in areas that subserve higher-order social, emotional and communication functioning. Such studies have concentrated on the most diagnostic features of autism by using theory of mind tasks and face processing tasks. However, the neurobiological substrate of such tasks is only partially understood and it is likely that such complex cognitive and perceptual abnormalities arise secondarily from more pervasive primary disturbances in neural connectivity. This study aims to use a more fundamental type of sensory input-the sense of touch-to further develop and refine the model of abnormal neural connectivity in autism. Hypothesis: 1)Compared to healthy controls, autistic adolescents will exhibit increased fMRI activity in primary and secondary somatosensory cortex and the anterior lobe of the right cerebellum in response to a self-produced tactile stimulus. 2)Compared to healthy controls, autistic adolescents will show decreased connectivity between somatosensory cortex and the cerebellum. 3) Variability in activity in primary and secondary somatosensory cortex and anterior lobe of the right cerebellum will be correlated to variability on performance on embedded figures task and susceptibility to visual illusions test.